Update {virtual,override} to follow C++11 style in chrome.

chrome/browser/devtools/device/usb/android_usb_browsertest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/devtools/device/adb/mock_adb_server.h"
 #include "chrome/browser/devtools/device/devtools_android_bridge.h"
@@ skipping 102 matching lines @@
 template <class T>
 class MockUsbDeviceHandle : public UsbDeviceHandle {
  public:
   explicit MockUsbDeviceHandle(MockUsbDevice<T>* device)
       : device_(device),
         remaining_body_length_(0),
         last_local_socket_(0),
         broken_(false) {
   }
 
-  virtual scoped_refptr<UsbDevice> GetDevice() const override {
+  scoped_refptr<UsbDevice> GetDevice() const override {
     return device_;
   }
 
-  virtual void Close() override { device_ = nullptr; }
+  void Close() override { device_ = nullptr; }
 
   void SetConfiguration(int configuration_value,
                         const ResultCallback& callback) override {
     NOTIMPLEMENTED();
   }
 
   void ClaimInterface(int interface_number,
                       const ResultCallback& callback) override {
     bool success = false;
     if (device_->claimed_interfaces_.find(interface_number) ==
@@ skipping 645 matching lines @@
   EXPECT_EQ(2, listener.invoked_);
   EXPECT_EQ(listener.invoked_ - 1, scheduler_invoked_);
   EXPECT_TRUE(base::MessageLoop::current()->IsIdleForTesting());
 }
 
 IN_PROC_BROWSER_TEST_F(AndroidUsbTraitsTest, TestDeviceCounting) {
   MockCountListenerForCheckingTraits listener(adb_bridge_);
   adb_bridge_->AddDeviceCountListener(&listener);
   runner_->Run();
 }